kernel: Build: Split kmod-regmap

This reduces the needed modifications to the mainline Linux kernel and
also makes the regmap package work with an out of tree kernel which
does not have these modifications.

The regmap-core is only added when it is really build as a module.
The regmap-core is normally bool so it cannot be built as a module in an
unmodified kernel. When it is selected by on other kernel module it will
always be selected as build in and it also does not show up in
$(LINUX_DIR)/modules.builtin as it is not supposed to be a kernel module.
When it is not in $(LINUX_DIR)/modules.builtin the build system expects
it to be built as a .ko file.
Just check if the module is really there and only add it in that case.

This splits the regmap package into multiple packages, one for each bus type.
This way only the bus maps which are really needed have to be added.
This also splits the I2C, SPI and MMIO regmap into separate packages to not
require all these subsystems to build them, on an unmodified upstream kernel
this also causes problems in some situations.

Signed-off-by: Hauke Mehrtens <hauke.mehrtens@intel.com>

1 files changed, 63 insertions, 24 deletions

diff --git a/package/kernel/linux/modules/other.mk b/package/kernel/linux/modules/other.mk
index cfb70553c3..220452df9b 100644
--- a/package/kernel/linux/modules/other.mk
+++ b/package/kernel/linux/modules/other.mk
@@ -30,7 +30,7 @@ $(eval $(call KernelPackage,6lowpan))
 define KernelPackage/bluetooth
   SUBMENU:=$(OTHER_MENU)
   TITLE:=Bluetooth support
-  DEPENDS:=@USB_SUPPORT +kmod-usb-core +kmod-crypto-hash +kmod-crypto-ecb +kmod-lib-crc16 +kmod-hid +!LINUX_3_18:kmod-crypto-cmac +!LINUX_3_18:kmod-regmap +!(LINUX_3_18||LINUX_4_9):kmod-crypto-ecdh
+  DEPENDS:=@USB_SUPPORT +kmod-usb-core +kmod-crypto-hash +kmod-crypto-ecb +kmod-lib-crc16 +kmod-hid +!LINUX_3_18:kmod-crypto-cmac +!LINUX_3_18:kmod-regmap-core +!(LINUX_3_18||LINUX_4_9):kmod-crypto-ecdh
   KCONFIG:= \
 	CONFIG_BT \
 	CONFIG_BT_BREDR=y \
@@ -172,7 +172,7 @@ define KernelPackage/eeprom-at24
   SUBMENU:=$(OTHER_MENU)
   TITLE:=EEPROM AT24 support
   KCONFIG:=CONFIG_EEPROM_AT24
-  DEPENDS:=+kmod-i2c-core +kmod-nvmem +LINUX_4_19:kmod-regmap
+  DEPENDS:=+kmod-i2c-core +kmod-nvmem +LINUX_4_19:kmod-regmap-i2c
   FILES:=$(LINUX_DIR)/drivers/misc/eeprom/at24.ko
   AUTOLOAD:=$(call AutoProbe,at24)
 endef
@@ -219,7 +219,7 @@ $(eval $(call KernelPackage,gpio-dev))
 define KernelPackage/gpio-mcp23s08
   SUBMENU:=$(OTHER_MENU)
   TITLE:=Microchip MCP23xxx I/O expander
-  DEPENDS:=@GPIO_SUPPORT +kmod-i2c-core +!(LINUX_3_18||LINUX_4_9):kmod-regmap
+  DEPENDS:=@GPIO_SUPPORT +kmod-i2c-core +!(LINUX_3_18||LINUX_4_9):kmod-regmap-i2c
   KCONFIG:= \
 	CONFIG_GPIO_MCP23S08 \
 	CONFIG_PINCTRL_MCP23S08
@@ -476,7 +476,7 @@ define KernelPackage/rtc-ds1307
   SUBMENU:=$(OTHER_MENU)
   TITLE:=Dallas/Maxim DS1307 (and compatible) RTC support
   DEFAULT:=m if ALL_KMODS && RTC_SUPPORT
-  DEPENDS:=+kmod-i2c-core +!(LINUX_3_18||LINUX_4_9):kmod-regmap +!(LINUX_3_18||LINUX_4_9):kmod-hwmon-core
+  DEPENDS:=+kmod-i2c-core +!(LINUX_3_18||LINUX_4_9):kmod-regmap-i2c +!(LINUX_3_18||LINUX_4_9):kmod-hwmon-core
   KCONFIG:=CONFIG_RTC_DRV_DS1307 \
 	CONFIG_RTC_CLASS=y
   FILES:=$(LINUX_DIR)/drivers/rtc/rtc-ds1307.ko
@@ -710,32 +710,71 @@ endef
 $(eval $(call KernelPackage,serial-8250-exar))
 
 
-define KernelPackage/regmap
+define KernelPackage/regmap-core
   SUBMENU:=$(OTHER_MENU)
   TITLE:=Generic register map support
-  DEPENDS:=+kmod-lib-lzo +kmod-i2c-core
-  KCONFIG:=CONFIG_REGMAP \
-	   CONFIG_REGMAP_MMIO \
-	   CONFIG_REGMAP_SPI \
-	   CONFIG_REGMAP_I2C \
-	   CONFIG_SPI=y
-  FILES:= \
-	$(LINUX_DIR)/drivers/base/regmap/regmap-i2c.ko \
-	$(LINUX_DIR)/drivers/base/regmap/regmap-mmio.ko \
-	$(if $(CONFIG_SPI),$(LINUX_DIR)/drivers/base/regmap/regmap-spi.ko)
-  AUTOLOAD:=$(call AutoLoad,21,regmap-core regmap-i2c regmap-mmio regmap-spi)
-  ifeq ($(strip $(CONFIG_EXTERNAL_KERNEL_TREE)),"")
-   ifeq ($(strip $(CONFIG_KERNEL_GIT_CLONE_URI)),"")
-    FILES += $(LINUX_DIR)/drivers/base/regmap/regmap-core.ko
-   endif
-  endif
+  HIDDEN:=1
+  KCONFIG:=CONFIG_REGMAP
+ifneq ($(wildcard $(LINUX_DIR)/drivers/base/regmap/regmap-core.ko),)
+  FILES:=$(LINUX_DIR)/drivers/base/regmap/regmap-core.ko
+endif
 endef
 
-define KernelPackage/regmap/description
+define KernelPackage/regmap-core/description
  Generic register map support
 endef
 
-$(eval $(call KernelPackage,regmap))
+$(eval $(call KernelPackage,regmap-core))
+
+
+define KernelPackage/regmap-spi
+  SUBMENU:=$(OTHER_MENU)
+  TITLE:=SPI register map support
+  DEPENDS:=+kmod-regmap-core
+  HIDDEN:=1
+  KCONFIG:=CONFIG_REGMAP_SPI \
+	   CONFIG_SPI=y
+  FILES:=$(LINUX_DIR)/drivers/base/regmap/regmap-spi.ko
+endef
+
+define KernelPackage/regmap-spi/description
+ SPI register map support
+endef
+
+$(eval $(call KernelPackage,regmap-spi))
+
+
+define KernelPackage/regmap-i2c
+  SUBMENU:=$(OTHER_MENU)
+  TITLE:=I2C register map support
+  DEPENDS:=+kmod-regmap-core +kmod-i2c-core
+  HIDDEN:=1
+  KCONFIG:=CONFIG_REGMAP_I2C
+  FILES:=$(LINUX_DIR)/drivers/base/regmap/regmap-i2c.ko
+endef
+
+define KernelPackage/regmap-i2c/description
+ I2C register map support
+endef
+
+$(eval $(call KernelPackage,regmap-i2c))
+
+
+define KernelPackage/regmap-mmio
+  SUBMENU:=$(OTHER_MENU)
+  TITLE:=MMIO register map support
+  DEPENDS:=+kmod-regmap-core
+  HIDDEN:=1
+  KCONFIG:=CONFIG_REGMAP_MMIO
+  FILES:=$(LINUX_DIR)/drivers/base/regmap/regmap-mmio.ko
+endef
+
+define KernelPackage/regmap-mmio/description
+ MMIO register map support
+endef
+
+$(eval $(call KernelPackage,regmap-mmio))
+
 
 define KernelPackage/ikconfig
   SUBMENU:=$(OTHER_MENU)
@@ -996,7 +1035,7 @@ $(eval $(call KernelPackage,echo))
 define KernelPackage/bmp085
   SUBMENU:=$(OTHER_MENU)
   TITLE:=BMP085/BMP18x pressure sensor
-  DEPENDS:= +kmod-regmap @!LINUX_3_18
+  DEPENDS:= +kmod-regmap-core @!LINUX_3_18
   KCONFIG:= CONFIG_BMP085
   FILES:= $(LINUX_DIR)/drivers/misc/bmp085.ko
 endef